I think this is my favorite way of creating sweet potato slips. It’s only May 1st so it’s not too late to start them this way, and if you are doing the “set the spuds on the counter and let them slip” method with moderate or even decent success, it’s not too late to switch out to this method for a boost. Just ordinary potting soil, barely DONT cover the spuds with the soil (let water carry some soil over them and then just leave that is fine), and then drown them with some purified or rain water. Keep the substrate wet but after the initial drowning don’t leave standing water in the container. #plantstr #grownostr 
Discussion
I like it.
This is how I do it
Sadly sweet potatoes are high in oxalates which are poisonous to humans. They taste good so you probably didn't know that.
I did, but after stacking studies that basically said everything is poison I stopped caring. Gotta eat!
I live on the wild side and eat swiss chard, undercooked eggs, overcooked meat from an open fire, and drink root beer made with real sassafras.
I also feed the greens to my meat rabbits, so I’m sure rabbit starvation will get me first.